Question

Write a program that lets the user enter a nonnegative integer then uses a loop to calculate the factorial of that number. Display the factorial.

Answer 1

Answer:

Following are the program in c++ language

#include <iostream> // header file

using namespace std;// namespace

int main() // main function

{

    int num; // variable declaration

    long int f=1; // variable declaration

   do

   {

       cout<<"Enter the Positive value:";

       cin>>num;

   } while(num<0); // i check whether   number is non negative or not

   while(num>0) // iterating over the loop

   {

       f=f*num; // calculate the factorial

       num--; // decrement the value of num by 1

   }

   cout<<" factorial is :"<<f; // display the factorial .

   return 0;

}

Output:

Enter the Positive value:7

factorial is :5040

Explanation:

Following are the description of the program .

• Read the input by user in the "num" variable of "int" type..
• The do-while will check the enter number is nonnegative number.  
• While(n>0) loop is calculating the factorial in the  "f" variable .
• Finally display the factorial .